1. Field of the Invention
The present invention relates to a memory card designed for reception in a memory card receptacle and into or from which information signal is to be written or read, and the memory card receptacle.
2. Description of Related Art
A well-known memory card incorporating memory chips in which information signals are stored is provided with terminals which are to electrically be connected with an external system. The memory card is supplied with a voltage through the terminals and also delivers and receives information signal to and from the internal memory chips through the terminals.
Since the terminals for connection of the memory card to an external system are also electrically connected to the internal memory chips, they should be protected from being touched when the memory card is used. More particularly, if the terminals are directly touched, a static electricity will take place in them, which however is a rare case, and be carried from the terminals to the memory chips which thus will possibly be broken down. To avoid this, the terminals should be protected against easy access to them from outside to prevent such a breakdown due to a static electricity
Also, the memory card of this type is featured by its transportability. So, it has been tried to design more compact memory cards for the convenience of portability. Thus, along with the more compact design of the memory card itself, its terminals have been designed thinner and arranged at reduced intervals.
Such thin, closely disposed terminals for connection an external system will possibly be deformed and broken even if just lightly touched.
To prevent the terminals from being deformed or broken down, a memory card of this type has been proposed in which such terminals are buried inside in the memory card body and small holes communicating with the terminals are formed in the memory card body so that the terminals are exposed to outside only through the holes, or in which a concavity is formed in a forward end portion of the memory card body in the card inserting direction and terminals are disposed in the bottom of the concavity for protection of them.
However, the memory card in which the small holes are formed in the card body for the terminals to be exposed to outside is hard to disconnect from the receptacle if the holes are clogged with dust or the like. When the memory card is inserted into the receptacle with the holes left clogged with dust, no positive connection with the receptacle can be attained and also the terminals of the receptacle may--possibly be deformed as the case may be.
Further, the above memory card is apt to have a complicated structure and is manufactured with large costs. Therefore, the conventional memory card is not suitable for mass production.
Also, in the memory card having formed in the body thereof the concavity in which the terminals are disposed, the protection of the terminals cannot be protected to a satisfactory extent if the concavity is improperly shaped. If the concavity is not shaped for a satisfactory protection of the terminals, dust or the like is likely to heap or stay in the corners of the concavity and block the terminals of the memory card from secure connection with those of the receptacle.
Further a memory card has been proposed which is cut at one of the corners of a generally rectangular body thereof to prevent the memory card from being inserted incorrectly (in a wrong direction or posture) into a memory card receptacle. In this case, however, the memory card cannot be designed to have a variety of shapes by chamfering or rounding, for example, the other three corners.
The present invention has an object to overcome the above-mentioned drawbacks of the prior art by providing a memory card having a simple structure, adapted to positively protect terminals thereof and easily let out dust or the like from inside to attain a positive connection with a memory card receptacle, and designable to have a variety of corner shapes, and the memory card receptacle.
The above object can be accomplished by providing a memory card comprising a body, a concavity formed in the card body which is open at the top and forward end of the card body in the inserting direction of the latter, and terminals disposed in the concavity. The memory card has also a projection formed in at least a part of a space defined between two successive ones of the terminals disposed in the concavity to protect the terminals against access or touch from outside, and the inner wall of the concavity perpendicular to the inserting direction of the card body is inclined.
In this memory card, the projections are formed in the concavity to define sockets in each of which a terminal is disposed, whereby the terminals thus disposed in the concavity can be protected against access or touch from outside.
Since the concavity has the inclined inner wall, dust or the like, if any, can easily be let out from on the concavity wall when the memory card is inserted into a memory card receptacle.
The above object can also be accomplished by providing a memory card comprising a body, a concavity formed in the card body and open at the top and forward end, in the inserting direction, of the card body, and terminals disposed in the concavity. The memory card has also a shutter member which opens and closes the concavity, and the inner wall of the concavity perpendicular to the inserting direction of the memory card is inclined.
When the memory card is not inserted into a memory card receptacle, the concavity is closed by the shutter member so that the terminals disposed inside the concavity cannot be accessed or touched from outside.
When the memory card is inserted into a memory card receptacle, dust or the like is removed to outside from the inclined wall of the concavity.
Also the above object can be accomplished by providing a memory card receptacle having a receiving concavity formed therein, a plurality of terminals disposed in the receiving concavity, and a plurality of projections provided ahead of the plurality of terminals correspondingly to the terminals of a memory card.
When the memory card is inserted into the receptacle, the projections go ahead of the receptacle terminals and slide on the memory card terminals to let out dust or the like from on the memory card receptacle.